The western blotting results showed that overexpression of PKM2 in both HCC cell lines promoted the expression of HIF-1α, and knockdown of PKM2 decreased the HIF-1α levels (Fig. 4c), while the changes of PKM2 had no effect on the expression of HSP90, which was probably because HSP90 was not the target gene of PKM2 or HIF-1α (PB2 may influence the levels of HSP90 through unknown mechanisms in the study, for example, PB2 may influence the stability or the degradation of HSP90). This evidence concerns the gene HIF1A and hepatocellular carcinoma.